The dsDNA bacteriophages are the most numerous taxon of evolving organisms in the biosphere. Information currently available from genomic sequencing of these organisms has revealed important insights into their evolution, and has given good reason to believe that a modest amount of additional sequence determination of whole genomes will substantially augment our understanding of the genetic structures of phage populations and of their evolutionary mechanisms and history. We propose to determine the sequences of nine bacteriophage genomes, three of the lambdoid family, four from the mycobacteriophages, and two others. We will analyze and compare the sequences to elucidate their genetic organizations and to make evolutionary inferences about the phages. In addition to providing evolutionary information for the bacteriophages, this project is expected to contribute to basic research on bacteriophage biology by providing comparative data about gene organization and function as well as by making new bacteriophages available for detailed experimentation. In addition, sequence data from this project is expected to assist in using bacteriophages to analyze and counteract human diseases caused by their hosts, specifically including tuberculosis.